(Click image to enlarge)

This page contains valuable information on the Infinity 902-2638, 902-6682, and 902-6758, and we are presently providing it as an aid to persons wanting to replace their blown Polycell tweeters.  We have discontinued selling the 902-2638, at present. But, please read the below and check with us for other alternatives! 

Update — 01/25/10:  We can now install new diaphragms in most 1-inch voice coil Polycell tweeter models. (List at bottom of page.)  Please Contact Us for more information.

Update – 12/28/09:  We recently discovered that at least some 902-2638′s that went on the market some years ago have a fatal flaw:  The lead-in wires from the terminals to the voice coil corrode just inside the solder joints to the terminals.  After several years, the wires fail, even if the tweeter has never been used.  (We have no idea how many users figured they just ”blew” their tweeters.)  So far as we know, this is undetectable unless, 1) The tweeter has failed; or, 2) The DC resistance reads high or inconsistent.  (See specs — the DCR should be around 6.4 ohms.)  At present we recommend you buy only 902-2638′s with diaphragms made after 2004, or which have had the lead wires replaced by a competent (in this case VERY competent) shop.  Or, consider an alternative with similar or better specifications for your application.  (See below for more information.)

Update — 9/20/11:  We discovered today that apparently some tweeters labelled “High Output” are NOT the large magnet Polycell tweeters.  More info. has been added here.

 

We have several pieces of the original Infinity High Output Poly-Cell 1″ Dome Tweeter, # 902-2638,  available.  These are brand new, never used* units, manufactured by Tonegen (Foster).
  

Features and Specifications of Infinity 902-2638:

Extremely efficient: Approx. 98+ dB/2.83v/1m.**  Infinity was not kidding when they labelled these “High Output”:  These are, quite simply, the most efficient 1″ non-horn loaded dome tweeters we have ever measured!!

Faceplate diameter: 3 11/16″ (3.693″ measured) / 93.8mm.

Magnet diameter: 2.75″ / 70.0mm.  (Cut hole slightly larger.)

8 ohm impedance.  DCR = 6.4 ohms.

Recommended (electrical) crossover: 18 dB/octave or steeper, at 5000Hz or higher.  (See further info. below.)

Comes with rear gasket attached for good air seal to cabinet. Std. 3mm / 1.18″ solder terminals. (See pics.)

Infinity Part No. 902-2638.  Very important!!!  This unit is NOT the same as the Infinity Part # 902-6682, the 902-5345, the 902-6758, or other smaller magnet versions.  The 902-2638  is completely different, with a much larger magnet and several dB more efficiency than some of the other models.  See below.**

 

1-2 pieces, $62.00 ea.,  3-4 pieces, $66.00 ea., 5+ pieces, $69.00 ea.

*We will of course do a operational (sweep) test on each unit, before shipping.

For additional Ordering Information please click here.

We have discontinued selling the 902-2638 at present. But, please read the below and also check with us for other alternatives! 

Please note that while the 902-2638 is a very excellent tweeter for crossing over at 5 kHz or above, with an 18 dB / octave or steeper high pass filter, we DO NOT recommend usage in two-way systems, even though we see used them in such systems (and users blow them frequently!)  The reason for this recommendation is that Infinity did not use tinsel leads in this tweeter, perhaps partially to help keep the efficiency maximized.  That, combined with the very high output, means that the single strand leads are very easy to break when used with high pass crossovers under 5 kHz.  For a much better choice of a replacement tweeter for 2-way Infinity speaker systems, please see our recommendations, below.  A great upgrade solution for 2-way systems is to revamp / upgrade the crossover and use a modern tweeter designed expressly for use in a low-crossover frequency 2-way system.  Contact Us for more information and alternatives.

Also note:  The 902-2638 is not, we repeat NOT, we repeat NOT(!) the same as the Infinity Part # 902-6682 which we see from other sellers on the Internet.  The # 902-6682 is nearly 10 dB less efficient, has a much smaller magnet, a 3/4″ voice coil, and there are likely other differences as well.   Other sellers have the Infinity Model # 902-6758, which we have been advised is the only Polycell tweeter Infinity presently offers as  a replacement for past Polycell tweeter models.  This is also a smaller magnet unit.  If you find it, or have one, take a look at the picture (or your unit) and the spacing between the terminals and the magnet.  Then compare to the rear picture of the 902-2638, below.

This is a rather unfortunate situation:  Infinity made many(!) Polycell tweeter models, with a very wide range of efficiencies, but, presently, only the small magnet 902-6758 replacement model is available.  Therefore, especially in the case of the high output Polycell tweeters, when used in 3-way systems, usually the best possible performance match will be obtained by having the diaphragm professionally replaced (see below.)  The next best choice is a 1” dome tweeter with as much efficiency as possible, and that is also a good choice when funds are limited, or when the original High Output Polycell tweeter is missing.  However, see our new page on the SM-150 and SM-155 models, which are a sort of “special case”.  (Coming soon!)

Our advice is that if you have one of the smaller magnet Polycell tweeters in your speakers, you probably should not put a # 902-2638 or a similar efficiency unit in, as a replacement, unless the tweeters you had sounded very dull, but played “ok” otherwise.  Replacing an original that has the smaller magnet with the large magnet version will likely lead to terribly “bright’ sound.  The reverse is also true:  If you replace a 902-2638 with a small magnet version, the sound will likely be very dead on the high end.  We have much better alternatives available.  Additionally, as noted above, if you have a 2-way system, we do not recommend the Polycell tweeters at all:  We have solutions with improved power handling.  See below. 

Recommendations:

For Infinity 2-way speaker system models using the smaller magnet Polycell tweeters:
Budget Option:  HiVi X1 (with 3 ohm resistor) (may require baffle hole / grill modification).
Best sound for the money:  Jamo 20300 (may require baffle hole / grill modification).
Direct drop-in:  Tonegen / Foster # 15069-61A 1-inch soft dome tweeter.  (Faceplate and screw holes match, may require enlargement of baffle hole in a few cases – see drawing on the 15069 page.)
Polycell diaphragm replacement:  Not recommended.  Contact us.

For Infinity 3-way speaker system models using the smaller magnet Polycell tweeters:
Budget option 1:   PR1C6B4SD-HE1 (With attenuation or L-pad for user to add if no L-pad is provided by Infinity.)  (May require enlargement of baffle hole / grille modification in some cases.)
Budget option 2:  Coming soon – JAMO 20452 1″ Soft Dome Tweeter  (May require enlargement of baffle hole / grille modification in some cases.)
Best sound for the money:  Jamo 20300 (may require baffle hole / grill modification.)
Direct drop-in#1: Tonegen / Foster # 15069-61A 1-inch soft dome tweeter.  (Faceplate and screw holes match, enlargement of baffle hole may be required in a few cases – see drawing on the 15069 page.) 
Direct drop-In#2:  PR-SB-TWD25NH-05-08-mod2 (for systems up to 98 dB sensitivity.*)  (Needs attenuation or L-pad for user to add if no L-pad is provided by Infinity.)   $28.00 ea.
Premium soultion:  Polycell diaphragm replacement:  Contact us.

For Infinity 2-way speaker system models using the larger magnet Polycell tweeters like the 902-2638:
Budget Option:  None at present.  Sorry!
Recommended (for systems up to 94 dB sensitivity and plenty of tweeter level adjustment range*): PR1C9SD-HE1  (May require slight enlargement of baffle hole / grille modification in some cases.)
  Or: PR1C9SD-HE2 (coming soon!)
Direct Drop-in:  None at present.  Sorry!  
Polycell diaphragm replacement:  Not recommended.  Contact us.
– Some of the Infinity 2-ways that used the High Output Polycell (or similar) tweeters are among the hardest of all speakers to properly repair “at a distance”.  We will be putting up a new page to offer more information and options for systems like these, soon.   In the meantime, please Contact us for assistance. –

For Infinity 3-way speaker system models using the larger magnet Polycell tweeters like the 902-2638, crossing over to the tweeter @ 5000 Hz or higher:
Budget option:  PR1C6B4SD-HE1 for systems up to 97 dB sensitivity.*) (May require slight grille modification in some cases.)
Best sound for the money: PR1C9SD-HE1 (for systems up to 95 dB sensitivity.*) (May require slight enlargement of baffle hole / grille modification in some cases.)
  Or: PR1C9SD-HE2 (coming soon!)
Direct Drop-In:  PR-SB-TWD25NH-05-08-mod2 (for systems up to 98 dB sensitivity.*)  $28.00 ea.
Premium solution:  Polycell diaphragm replacement:  Contact us.

*The published sensitivity specs on some Infinity speaker systems seem a little generous.  Generally, if your speaker has a tweeter level control, and a woofer of 10″ or smaller, a tweeter with a sensitivity rating of 95-96 dB (ref. 8 ohms) will work fine.  We are attempting to research the Infinity specs further — according to at least one source who says a competent shop ran curves on their SM series speaker, the Infinity sensitivity rating was approx. 3 dB “too high”…

 

Replacement Diaphragms: 

Polycell tweeters with a 1″ voice coil that we can* re-diaphragm (new dome and voice coil “butterfly” assembly):  902-0925, 902-2107, 902-2347, 902-2616, 902-2638, 902-2722, 902-4270, 902-4606, 902-5072, 902-5345, 902-6328, 902-6412, 902-6688, 902-6758, 902-7683, and there may be others.  Infinity used MANY models of Polycell tweeters over the years, and we are sure we have not seen all of them!

Not all Polycell tweeters have a 1″ voice coil – please Contact Us before sending us your tweeter(s)!

*We also cannot guarantee that Infinity never “made a change on the fly” to any model listed above, so, again, please Contact Us before sending us your tweeter(s).

We MAY be able to get diaphragms for some of the 3/4″ coil models — please Contact Us for availability.
 
 

More 902-2638 Pics (click on the images to enlarge):